Underlying quality dimensions of modern telephone connections

It is the aim of the present paper to analyze the perceptual quality dimensions of modern telephone connections. Such connections differ from standard connections in their timevariant characteristics (e.g., due to Voice-over-IP transmission or due to noise reduction algorithms) and their user interfaces (e.g., hands-free terminals). With the help of two independent auditory experiments with subsequent multidimensional analyses, three perceptual dimensions were identified for a diverse set of stimuli. These dimensions were labeled “directness/frequency content”, “continuity”, and “noisiness”. Overall listening quality scores were collected in a separate experiment. A mapping of the obtained dimensions onto the overall listening quality scores by means of a linear model revealed that “continuity” appears to be the most important dimension in terms of overall listening quality.